What we don’t know is shaped by what we do. Whatever dark matter is, we will look for it assuming an accelerating, expanding universe. However cancer can be truly defeated, we will have to outsmart evolution to do so. And no matter what bizarre creatures are still to be discovered in our densest forest and deepest ocean depths, they are unlikely to ever be Bigfoot, Nessie, or the Chupacabra.
We have found monsters before. As biology has gotten better at tracking down the beasts that elude us, unlikely legends are becoming real animals. Just recently, we finally obtained amazing footage of two very mysterious creatures—the giant squid and the oarfish. They didn’t appear from nowhere either. Over the years biologists and fisherman have found traces of their existence, from fins and tentacles to intact bodies. This is how we find rare creatures in huge areas—we follow the evidence.
Cryptozoological creatures like Nessie and Bigfoot are both (supposedly) large animals living in large areas, and both have decades of “evidence” to suggest that we might film one someday—as we did the giant squid. But practicing biologists still consider these mythic animals’ existence to be highly unlikely. Why? In science, the kind of evidence matters; all unlikelihoods are not created equal.
Just because it may be "unlikely," doesn't preclude it from being real. To read more, click here.